The 40 Ar‐ 39 Ar laser analysis of K‐feldspar: Constraints on the uplift history of the Grenville Province in Ontario and New York

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95104/1/jgrb13261.pd

Pairing virtual reality with dynamic posturography serves to differentiate between patients experiencing visual vertigo

<p>Abstract</p> <p>Background</p> <p>To determine if increased visual dependence can be quantified through its impact on automatic postural responses, we have measured the combined effect on the latencies and magnitudes of postural response kinematics of transient optic flow in the pitch plane with platform rotations and translations.</p> <p>Methods</p> <p>Six healthy (29–31 yrs) and 4 visually sensitive (27–57 yrs) subjects stood on a platform rotated (6 deg of dorsiflexion at 30 deg/sec) or translated (5 cm at 5 deg/sec) for 200 msec. Subjects either had eyes closed or viewed an immersive, stereo, wide field of view virtual environment (scene) moved in upward pitch for a 200 msec period for three 30 sec trials at 5 velocities. RMS values and peak velocities of head, trunk, and head with respect to trunk were calculated. EMG responses of 6 trunk and lower limb muscles were collected and latencies and magnitudes of responses determined.</p> <p>Results</p> <p>No effect of visual velocity was observed in EMG response latencies and magnitudes. Healthy subjects exhibited significant effects (<it>p </it>< 0.05) of visual field velocity on peak angular velocities of the head. Head and trunk velocities and RMS values of visually sensitive subjects were significantly larger than healthy subjects (<it>p </it>< 0.05), but their responses were not modulated by visual field velocity. When examined individually, patients with no history of vestibular disorder demonstrated exceedingly large head velocities; patients with a history of vestibular disorder exhibited head velocities that fell within the bandwidth of healthy subjects.</p> <p>Conclusion</p> <p>Differentiation of postural kinematics in visually sensitive subjects when exposed to the combined perturbations suggests that virtual reality technology could be useful for differential diagnosis and specifically designed interventions for individuals whose chief complaint is sensitivity to visual motion.</p

Floor composition affects performance and muscle fatigue following a basketball task

On compare la fatigue musculaire ressentie et objective (EMG) lors d'une tâche simulée de basket effectuée sur un sol en parquet ou sur un sol plus souple en matériaux composites

Comparison of garnet-biotite, calcite-graphite, and calcite-dolomite thermometry in the Grenville Orogen; Ontario, Canada

The Elzevir Terrane of the Grenville Orogen in southern Ontario contains metapelites and abundant graphitic marbles that were regionally metamorphosed from the upper greenschist to upper amphibolite facies. Comparative thermometry was undertaken with widely used calibrations for the systems garnet-biotite, calcite-dolomite, and calcite-graphite. Temperatures that are obtained from matrix biotites paired with prograde garnet near-rim analyses are usually consistent with those determined using calcite-graphite thermometry. However, calcite-graphite thermometry occasionally yields low temperatures due to lack of equilibration of anomalously light graphite. Application of calcite-graphite and garnet-biotite systems may yield temperatures up to 70 °C higher than calcite-dolomite in amphibolite facies rocks. Calcite-dolomite temperatures most closely approach those from calcite-graphite and garnet-biotite when the samples contain a single generation of dolomite and calcite grains contain no visible dolomite exsolution lamellae. However, some of these samples yield temperatures considerably lower than temperatures calculated from calcite-graphite and garnet-biotite thermometry, indicating that the calcite-dolomite thermometer may have been partially reset during retrogression. Estimated peak metamorphic temperatures of regional metamorphism between Madoc (upper greenschist facies) and Bancroft (upper amphibolite facies) range from 500 to 650 °C. These results place the chlorite-staurolite isograd at 540 °C, the kyanite-sillimanite isograd at 590 °C, and the sillimanite-K-feldspar isograd at 650 °C. Although each thermometer may have an absolute uncertainty of as much as ±50 °C, the 50 to 60 °C temperature differences between the isograds are probably accurate to 10 to 20 °C. An incomplete picture of the thermal gradients can result from the application of only one thermometer in a given area. Simultaneous application of several systems allows one to recognize and overcome the inherent limitations of each thermometer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42225/1/410-134-2-3-217_91340217.pd

Improving Work Ability and Return to Work among Women on Long-term Sick Leave

The overall aim of this thesis was to gain new knowledge of factors and interventions that improve work ability and return to work (RTW) among women on long-term sick leave from human service organizations (HSOs). The specific aims of the studies were: to evaluate the associations between the self-rated Work Ability Index (WAI) and Work Ability Score (WAS), and the relationship with prospective sick leave, symptoms, and health (Paper I); to investigate whether intervention with myofeedback training or intensive muscular strength training could decrease pain and increase work ability among women with neck pain (Paper II); to examine the associations between workplace rehabilitation and the combination of supportive conditions at work with work ability and RTW over time (Paper III); and to explore experiences, views, and strategies in the rehabilitation process for RTW (Paper IV). This thesis is based on a prospective cohort study (n=324) and a randomized controlled study (RCT) (n=60, participants with neck pain). Both quantitative and qualitative methods were used. The data collection consisted of questionnaires, laboratory-observed data, register-based data, and interviews. The results showed a very strong association between WAI and WAS, and results predicted future sick leave degree, health-related quality of life, vitality, neck pain, self-rated general health, self-rated mental health, behavioral stress, and current stress (Paper I). In the RCT (Paper II), individuals in the myofeedback intervention group increased their vitality and work ability over time and individuals in the intensive musculoskeletal strength training group increased their WAI, WAS, and mental health over time. WAI, WAS, and RTW increased over time among individuals provided with workplace rehabilitation and supportive conditions at work (Paper III) such as a sense of feeling welcome back at work, influence at work, possibilities for development, degree of freedom at work, meaning of work, quality of leadership, social support, sense of community, and work satisfaction. Women described (Paper IV) how they were striving to work and how they had different views, strategies, and approaches in the rehabilitation process for RTW. They expressed a desire to work, their goals for work, and their wishes for work. In the rehabilitation process for RTW they described their interaction with stakeholders as either controlling the interaction or struggling in the interaction. They described strategies to cope with RTW in terms of yo-yo (fluctuating) working: yo-yo working as a strategy or yo-yo working as a consequence. This thesis identifies factors of importance in improving work ability and RTW among women on long-term sick leave from HSOs. For women with neck pain, the intervention study showed feasibility of the intervention and demonstrated improved work ability and decreased pain (Paper II). The intensive muscular strength training program, which is easy for the individual to learn and perform at home, was associated with increased work ability. The results regarding rehabilitation highlight the importance of integrating workplace rehabilitation with supportive conditions at work to increase work ability and improve RTW (Paper III). Women expressed that they were striving to work and that they wanted to work (Paper IV). These women were “going in and out” of work participation (yo-yo working) as a way to handle the rehabilitation process. For assessing the status and progress of work ability among women on long-term sick leave, the single-question WAS may be used as a compliment to the full WAI as a simple indicator (Paper I)